my datatable in flutter from json repeat the column headers

1import 'package:flutter/material.dart';
2import 'dart:convert';
3import 'package:json_table/json_table.dart';
4
5class SimpleTable extends StatefulWidget {
6  @override
7  _SimpleTableState createState() => _SimpleTableState();
8}
9
10class _SimpleTableState extends State<SimpleTable> {
11  final String jsonSample =
12      '[{"equipe1":"PSG","equipe2":"DIJON","type_prono":"1N2"},{"equipe1":"MONACO","equipe2":"REIMS","type_prono":"1N2"},{"equipe1":"TOULOUSE","equipe2":"RENNES","type_prono":"1N2"},{"equipe1":"MONTPELLIER","equipe2":"STRASBOURG","type_prono":"1N2"},{"equipe1":"AMIENS","equipe2":"METZ","type_prono":"1N2"},{"equipe1":"BREST","equipe2":"ANGERS","type_prono":"1N2"},{"equipe1":"LORIENT","equipe2":"CHAMBLY","type_prono":"1N2"}]';
13  bool toggle = true;
14
15  @override
16  Widget build(BuildContext context) {
17    var json = jsonDecode(jsonSample);
18    return Scaffold(
19      body: Container(
20        padding: EdgeInsets.all(16.0),
21        child: toggle
22            ? Column(
23          children: [
24            JsonTable(
25              json,
26              showColumnToggle: true,
27              tableHeaderBuilder: (String header) {
28                return Container(
29                  padding: EdgeInsets.symmetric(
30                      horizontal: 8.0, vertical: 4.0),
31                  decoration: BoxDecoration(
32                      border: Border.all(width: 0.5),
33                      color: Colors.grey[300]),
34                  child: Text(
35                    header,
36                    textAlign: TextAlign.center,
37                    style: Theme.of(context).textTheme.display1.copyWith(
38                        fontWeight: FontWeight.w700,
39                        fontSize: 14.0,
40                        color: Colors.black87),
41                  ),
42                );
43              },
44              tableCellBuilder: (value) {
45                return Container(
46                  padding: EdgeInsets.symmetric(
47                      horizontal: 4.0, vertical: 2.0),
48                  decoration: BoxDecoration(
49                      border: Border.all(
50                          width: 0.5,
51                          color: Colors.grey.withOpacity(0.5))),
52                  child: Text(
53                    value,
54                    textAlign: TextAlign.center,
55                    style: Theme.of(context).textTheme.display1.copyWith(
56                        fontSize: 14.0, color: Colors.grey[900]),
57                  ),
58                );
59              },
60              allowRowHighlight: true,
61              rowHighlightColor: Colors.yellow[500].withOpacity(0.7),
62              paginationRowCount: 20,
63            ),
64            SizedBox(
65              height: 20.0,
66            ),
67            Text("Simple table which creates table direclty from json")
68          ],
69        )
70            : Center(
71          child: Text(getPrettyJSONString(jsonSample)),
72        ),
73      ),
74      floatingActionButton: FloatingActionButton(
75          child: Icon(Icons.grid_on),
76          onPressed: () {
77            setState(
78                  () {
79                toggle = !toggle;
80              },
81            );
82          }),
83    );
84  }
85
86  String getPrettyJSONString(jsonObject) {
87    JsonEncoder encoder = new JsonEncoder.withIndent('  ');
88    String jsonString = encoder.convert(json.decode(jsonObject));
89    return jsonString;
90  }
91}
92
93void main() => runApp(MyApp());
94
95class MyApp extends StatelessWidget { 
96  @override
97  Widget build(BuildContext context) {
98    return MaterialApp(
99      title: 'Flutter Demo',
100      theme: ThemeData(      
101        primarySwatch: Colors.blue,
102      ),
103      home: SimpleTable(),
104    );
105  }
106}
107